Method of charging electric furnaces.



A11. ROBINSON. METHOD OF CHARGINGELEGTRIO FURNACES. 1122110 111011 2111111) 11111. e, 1 11.

1,QO4A6Q1 v Patented Sept. 26,1911.

11v VENTOR I LIITNESSES A Home ALFRED L. ROBINSON, OF NIAGARA FALLS, NE'W YORK, ASSIGNOE T INTERNATIONfiL ACHESON GRAPHITE COMP ANY, OF'NIAGARA FALLS, ,NEW YORK, A CORPORATION OF NEW JERSEY.

Mnrnon or CHARGING nnncrnic FURNACES.

Specification of Letters Patent. I Patented Sept, 26, i9

Application filed January 6, 1911: Serial No 601,137.

To all whom it may concern: I

Be it known that I, ALFRED L. ROBiNfiON, a citizen of the United States, residing at Niagara Falls, in the county of. Niagara and State. oiNcw York, have invented certain new and useful Improvements in Methods of Charging Electric Furnaces, of which the following is a-specification.

This, invention relates to the manufacture of refractory products, such as graphite,

polymerized carbon, etc, in the electric furnace, the object ofth'e inventionbeing the provision'of a method whereby the recovery of the product, in a commercially pure state and substantially free fromextraneous matters, may be made more nearly complete than has heretofore been possible:

invention will be "particularly described by reference to the production t what is known in the art as"'"bullt graphite, by heating commercial forms of'carbon in the electric furnace.

As is'well' known, it is necessary in the conversion of carbon into graphite in electrically heated furnaces that the carbon should be shielded from the direct action of the air while the free escape of distillation "gasesis pcrmitted-. This result is u sually attained in practice by heating the carbon while surrounded by or embedded in a granular refractory material of relatively low electrical conductivity, as for example a granular mass of carborundiun, white crust or incompletely converted carborundum charge,.sand and coke, .or the like. Under the usual. operating conditions,itis practically impossible to maintain a sharply defined plane or surtace of demarcahon between the carbonaceous charge and the surrounding or embedding layer of refractory H material, the diihculty being most pronounced at and near the. upper and lower surfaces ot'thn charge; and 'it is therefore usually necessary, in unloading each tur nace charge, to discard a considerable mass of material by reason of the admixture therewith of particles ofthe refractory embedding layei'. proceeding in accord ance with the present invention this ditlicultyto a large degree obviated, and the percentage recovery of pure raphite from each furnace run is materially increased.

Reference is made to thoiiccrn'npanying drawing, whereinz' Figure 1 is a transverse section of a typical. furnace charge as prepared in accordance with my invention; andFig. 2 is a similar view illustrating a modification of the mode of charging illustrated in F1.

"'In said drawing, 1 represents the base of an electric furnace whereof the charge to be transformedinto graphite is composed of suitable carbonaceous material 2, as for example crushedpetroleum-coke, gas-coke, coal or the like. p

.8 represents a starting core of carbon or graphite rods or bars, whichis usedin case the initial conductivity of the charge is low.

4.- indicates the embedding material, which as shown completely surrounds the carbon,

and is laterally supported by walls 5.

These walls may be of fire-briclr-loosely as sembled in order that the distillation gases may readily escape and burn.

Immediately adjacent the carbonaceous portion of the charge, and eitheh completely surrounding the same, as shown in Fig. 2', or in contact with its upper and lower surfaces only, as illustrated in Fig. ,1, I dispose a relatively th n layer or layers of a mate rial or mixture which under the o eratln-g' conditions of the furnace will cake into a mass sufiicientlystrong and solid to serve as a protection to the'chargefrom the overlying and underlying loose material. A suitable mixture for this purpose comprises about 25 per cent. of a bituminous material, as for example bituminous coal, pitch, or the like, I

Bituminous coal 25 parts. Ground coke 5O parts. Ground furnace crust- ;25 parts.

The ground furnace crust consists largely V of carborundum and intermediate reduction products of silica, as siloxicon, etc.

I prefer in charging the furnace to avoid admixture of the carbonaceous charge with the portion of the embedding material lying at the sides thereof by the use of vertical 190i .i'O biiuminou Upper and bonzaceoiie e Hie " n or 22:: bed

cm the 13 min In tins the nl y of the ed. SlfiEZ mixing n 0.! biilmzinous mate- )eei'ed use it; becomes teo xving to its progressive 11, when ii; is oils-carded.

i he embedceeied carbon is then furnace. after which ithe T, 4 rg 1n il/etiaer-s 102116 be read Wit the case in the i a this em'rmnion therein .4

Illiliiiflifli, an intemzeviiate layer of material differing frem said charge and embedding material. and; adapted. to become caked 01 solidified under the furnacing conditions.

2, The method 01 charging electric furnaces, which censlsts 111 disposing the charge {(0 be treated and an embedding material a layer comprising bituminous matter and a relractoiy filler.

3. The merhpd of preparing charges for graphitimiion, which consis ts in disposing between. a body of CEII'bO-Il and a refractory embedding mate ial, in intermediate layer of material dih'ei'ing from said charge and embeciding material and adapted to'become' Baked 0isolidified under the ditions.

' Q. The method of preparing charges for graphitization, which consists in disposing between a body of carbon and a refractory embedding materiei, a layer comprising bitmnineus mafia and '& refractcry fillen Indestimony whereof, I aflix my signature in presence of two Witnesses.

ALFRED L, ROBINSON furniicing 0011- A1,. Aci'zzesoir SMITH,

.Eieetric im'neeesfl e ror appears in may conform to the F... IvlUORE,

am'saa'mm of Patents. 

